and no doctor knew why? what would you do? "360" m.d. sanjay gupta introduces us tonight to the disease detectives, trying to solve medicine's toughest mysteries. that's part one of a week-long series. we begin tonight, though, keeping them honest with christine o'donnell and how she spent money from her last campaign. last week after searching federal campaign filings we learned that the surprise republican nominee for u.s. senator from delaware had checks and expense records that didn't seem to add up. apparently, spending campaign money on personal expenses after the campaign was over, which would be a violation of federal election law. for instance, take a look. this check for $475. ms. o'donnell labeled it as "mileage reimbursement." but it was written three months after her last campaign ended. or this, $600 for her utility bill, paid to delmarva power. again, the campaign was over. tonight, more checks have surfaced, including campaign dollars to pay rent on ms. o'donnell's home, rent going to her campaign lawyer and former boyfriend, who bought the home from her when she could n